A number of diseases and disorders in humans and other mammals are characterized by the build-up of excessive fluid pressure within one or more body cavities. In many instances, implantable devices or surgical procedures may be used to shunt excessive fluid from the body cavity wherein the excessive pressure build up is present, to one or more other sites within the body, as a means of receiving the undesirable pressure buildup, and thereby deterring the development of undesirable sequelae which may result from such pressure build-up.